1. Field of the Invention
The present invention relates to an image processing apparatus, a program, a recording medium, and an image editing method.
2. Description of the Related Art
Conventionally, as is described below, there are two types of processes that are commonly performed for displaying/editing electronic documents and images in a server-client electronic document management system or a server-client image management system.
With the first type, an image managed by a server computer is transmitted in the form of encoded data to a client computer so as to be decoded and displayed in the client computer. In the client computer, the image is subjected to an image editing process (e.g., rotating or flipping of the image), and the edited image is encoded and transmitted to the server computer in the form of encoded data, thereby replacing the image (encoded data) managed in the server computer.
With the second type, an image managed by a server computer is transmitted in the form of encoded data to a client computer to be decoded and displayed in the client computer. The image editing process (e.g. rotating or flipping of the image) is performed on the image by sending an editing command from the client computer to the server computer. That is, the sequential processes of decoding→editing (rotating/flipping)→encoding is performed in the server computer in response to the editing command sent from the client computer.
The above-described two types are often used separately depending on the editing purpose. For example, complicated image editing processes such as cutting-out a portion of an image or cutting & pasting of another image are often performed in the client computer as described in the first type. In a case where an image editing process involving the entire image (e.g. rotating) is performed at once on a plurality of images, the image editing process is often performed in the server computer as described in the second type.
In order to fulfill the recent needs for enhancing performance and increasing functions in image compression/decompression technology, JPEG 2000, which is a new image compression format capable of decoding high-grade images even under high compression rates, is being standardized. With JPEG 2000, compression/decompression can be accomplished even under limited memory conditions by dividing images into rectangular areas (tiles). That is, each tile serves as a basic unit for performing compression/decompression where the compression/decompression can be performed on each tile independently.
The JPEG 2000, however, has a complicated algorithm, and requires longer time in encoding and decoding compared to the conventional JPEG.
Processing time is, particularly, a factor that cannot be ignored when performing an image editing process (e.g., rotating) entirely to a plurality of images.
In JPEG 2000, only the tiles, which have been renewed in editing a portion of an image, need to be replaced since compression/decompression can be performed independently on each tile, thereby allowing processing time to be reduced. However, when a plurality of images are to be subjected to an image editing process (e.g., flipping of an entire image) requiring renewal of an entire image, processing time cannot be reduced merely by dividing images into tiles since the entire image is to be replaced.